Isoquinuclidine derivative process for producing the same, and medicinal composition containing the same

ABSTRACT

An isoquinuclidine derivative represented by the following general formula (I): (I) [wherein A 1  is methylene or carbonyl]: R 1  is hydrogen or methyl: R 2  is —(CH 2 ) n -A 2 -Ph (n is an integer of 0 to 3 and A 2  is a single bond or —O—): and R 3  is —COOH, —COOR 4 , —COSR 4  (R 4  is lower alkyl, unsubstituted phenyl, or phenyl substituted by a lower alkyl, lower alkoxy, hydroxyl, methoxycarbonyl, ethoxycarbonyl, or trifluoromethanesulfonamide group or by a halogen atom), etc.] or a pharmaceutically acceptable salt of the compound. Also provided is an oral remedy for diabetes, which contains the compound and has hypoglycemic activity.

CROSS REFERENCE TO RELATED APPLICATION

This application is a § 371 application of PCT/JP02/02847 filed on Mar.25, 2002, which claims foreign priority to JP 2001/88635 filed on Mar.26, 2001.

FIELD OF THE INVENTION

This invention relates to the novel isoquinuclidine derivatives whichhave an blood glucose lowering effect, or the pharmaceuticallyacceptable salts using as therapeutic and preventive agents of diabetesor diabetic complications, and the production method, further relates toa pharmaceutical composition containing these isoquinuclidinederivatives or the salts as active ingredients.

BACKGROUND OF THE INVENTION

In a treatment of diabetes, an improvement of life-style such as dietand exercise is important but insulin or oral antidiabetic agents havebeen used to gain more sufficient effect. Biguanide and sulfonylureaderivatives have been used as antidiabetic agents so far, and recently,suger absorption inhibitory agents, insulin enhancing agents, andinsulin-secretion stimulants have been developed.

However, sulfonylurea agents cause severe and prolonged hypoglycemia asside effect and biguanide agents also cause fatal lactic acid acidosis.Furthermore, suger absorption inhibitory agents are weakly blood glucoselowering effect and it is reported that insulin enhancing agents causesevere hepatitis. As in the present, oral antidiabetic agents which areused at present, have several defects such as the side effects. In thiscircumstance more safety and effective agents are desired.

The object of the present invention is the provision of the novelisoquinuclidine derivatives which have an blood glucose loweringactivities, or the pharmaceutically acceptable salts using astherapeutic and preventive agents of diabetes or diabetic complications,and the production method, further a pharmaceutical compositioncontaining these isoquinuclidine derivatives or the salts as activeingredients.

DETAILED DESCRIPTION OF THE INVENTION

After elaborated to make an oral antidiabetic drug which has a potentblood glucose lowering activity and a safety, the inventor found thatthe compound as show general formula (I) had shown a hypoglycemicactivity.

Namely, the invention is the compounds as shown in general formula (I)and its pharmaceutically acceptable salts and a composition containingthese compounds as active ingredients for a treatment and/or priventionof diabetes.

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogene ormethyl group, and R₂ represents —(CH₂)_(n)-A₂-Ph (n denotes an integerof 0-3 and A₂ is single bond or —O—). R₃ represents —COOH, —COOR₄, or—COSR₄ (R₄ represents lower alkyl, non-substituted phenyl group, orphenyl group which is substituted with lower alkyl, lower alkoxy,hydroxy, methoxycarbonyl, ethoxycarbonyl, trifluoromethanesulfoneamide,or halogen), —CONHR₅ (R₅ represents pyridyl, thiazolyl, nonsubstitutedphenyl group, or phenyl group which is substituted with lower alkyl,lower alkoxy, hydroxy, methoxycarbonyl, ethoxycarbonyl,trifluoromethanesulfoneamide, or halogen), —NHR₆ (R₆ is —SO₂—R₇ (R₇represents lower alkyl, —CH₂COOH, trifluoromethyl, non-substitutedphenyl, phenyl group which is substituted with lower alkyl, loweralkoxy, hydroxy, or halogen), or —CO—(CH₂)_(m)-R₈ (m=0 or 1, R₈represents carboxyl group, non-substituted phenyl, or phenyl group whichis substituted with lower alkyl, lower alkoxy, carboxyl, hydroxy,halogen, —NHSO₂CF₃, or —NHCOCOOH), —P(O)(O-iPr)₂, —CH(R₉)COOH(R₉represents hydrogen, hydroxy, or —OR₁₀ (R₁₀ is lower alkyl, —CH₂OCH₃,—CH₂O(CH₂)₂OCH₃, or —CH₂SCH₃)), —CH₂CH(COOH)₂, —SO₃H, or a followingformula

(wherein A₃ is hydrogen or methyl)or a pharmaceutical acceptable salt. Oral anti-diabetic agentscontaining the compounds of general formula (I) or its pharmaceuticallyacceptable salts as active ingredients which have blood glucose loweringactivity.Typical preparation of the compounds according to the invention areshown in table 1-11, but they are not limited to these compounds.

TABLE 1 No. Structure mp (° C.) 1

93-95 2

171-172 3

69-72 4

140-142 5

60-65

TABLE 2 No. Structure mp (° C.) 6

117-119 7

115-117 8

oil 9

250-255 10

232-235

TABLE 3 No. Structure mp (° C.) 11

>250 12

oil 13

oil 14

92-95 15

112-113

TABLE 4 No. Structure mp (° C.) 16

155-158 17

oil 18

61-64 19

130-132 20

190-192

TABLE 5 No. Structure mp (° C.) 21

156-159 22

149-151 23

127-129 24

128-130 25

129-130

TABLE 6 No. Structure mp (° C.) 26

129-130 27

128-129 28

60-62 29

136-138 30

100-103

TABLE 7 No. Structure mp (° C.) 31

oil 32

oil 33

78-80 34

79-80 35

200-201

TABLE 8 No. Structure mp (° C.) 36

52-53 37

79-81 38

118-120 39

84-85 40

78-80

TABLE 9 No. Structure mp (° C.) 41

60-61 42

oil 43

oil 44

oil 45

oil

TABLE 10 No. Structure mp (° C.) 46

oil 47

171-174 48

oil 49

oil 50

oil

TABLE 11 No. Structure mp (° C.) 51

156-158 52

153-155 53

148-151

The compound of general formula (I) can be obtained as follows.

-   (A) In the compound of general formula (1), the compound of general    formula (III) is prepared by the following reactions.    (wherein R₂ and R₁₁ are the same as mentioned above.)

The compound of general formula (XX) is reacted with PivCl (pivaloylchloride) in the presence of organic base such as Et₃N (triethylamine)or NMM (N-methylmorpholine) in THF to obtain a mixed anhydride, followedby the reaction with 4(S)— or 4(R)-benzyl-2-oxazolidinone in thepresence of n-butyl lithium or LiCl to afford the compound of generalformula (XXI). Subsequently, the compound of general formula (XXI) isconverted to the compound of general formula (XXII) by an asynmmetricalhylation with the tert-butyl bromoacetate in THF using LHMDS (lithiumhexamethyl disilazane) or LDA (lithium diisopropylamide) etc. Then thecompound of general formula (II) is obtained by deprotection of thetert-butyl group using an acid such as TFA (trifluoroacetic acid) or HCletc. in THF. Furthermore, the compound of general formula (XXIII) isobtained by the reaction with isoquinuclidine hydrochloride using acoupling reagent such as DEPC (diethylphosphoryl cyanide), DPPA(diphenylphosphoryl-azide), WSCDI(1-(3-dimethylarmrinopropyl)-3-ethylcarbodiimide. HCl salt), DCC(dicyclohexyl-carbodiimide) etc. in the presence of organic base such asEt₃N or NMM etc. in THF or DMF. The chiral auxiliary (4-(S—) or4-(R)-Benzyl-2-oxazolidinone) is removed by using of lithium hydroxideand hydrogene peroxide in THF to give the compound of general formula(III).

The compound of general formula (III) is also obtained by the samereaction using 1(S) or 1(R)-2, 10-camphersultam instead of 4(S) or4(R)-benzyl-2-oxazolidinone.

-   (B) In the compound of general formula (I), the compound of general    formula (VII) is prepared by the following reactions.    (wherein R₂ is the same as mentioned above.)

The chiral auxiliary of general formula (XXII) is removed to obtain thecompound of general formula (XXIV). The obtained compound of generalformula (XXIV) is reacted with methyl iodide using an base such asLHMDS, LDA etc. to afford the compound of general formula (XXV). Then,the compound of general formula (XXVI) is obtained by the esterificationof the carboxylic acid group of general formula (XXV), followed by thedeprotection of the tert-butyl group with acids such as HCl or TFA etc.and the condensation with isoquinuclidine hydrochloride. The obtainedcompound of general formula (XXV) is hydrolyzed by lithium hydroxideetc. in THF/H₂O to give the compound of general formula (VII).

-   (C) In the compound of the general formula (I), the compound of    general formula (V) is prepared by the following reactions.    -   (wherein R₂ and R₁₁ are the same as mentioned above.)

The carboxylic acid group of general formula (II) is reduced with boranedimethylsulfide etc. to afford the compound of general formula (XXVII).Then, the compound of general formula (XXVII) is mesylated or tosylatedto obtain the compound (XXVIII) with MsCl (methanesulfonyl chloride) orTsCl (p-toluenesulfonyl chloride) in the presence of base such astriethylamine, pyridine etc. in dichloromethane. The resulting compound(XXVIII) is reacted with isoquinuclidene hydrochloride in the presenceof base such as triethylamine, potassium carbonate etc. indichloromethane and DMF etc. and obtained the compound of generalformula (XXIX). After removal of the chiral auxiliary in the compound(XXIX), the compound of general formula (V) was obtained.

The compound (XXIX) is also obtained by the chlorination of the compound(XXVII) with PPh₃/CHBr₃ or SO₂Cl/C₆H₆ and followed by the amination withisoquinuclidine.

-   (D) In the compound of the general formula (I), the compound of    general formula (IX) is prepared by the following reactions.    -   (wherein R₁, R₂, R₄, R₅ and R₁₄ are the same as mentioned        above.)

The compound of general formula (IX) is obtained by the reaction withthe compound of general formula (VIII) and R₄OH, R₄SH, or R₅NH₂ usingthe coupling agent such as DEPC, DPPA, WSCDI and DCC.

-   (E) In the compound of general formula (I), the compound of general    formula (XII) is prepared by the following reactions.    (wherein R₁, R₂, R₆, R₇, R₈, R₁₂ and R₁₃ are the same as mentioned    above.)

The compound of general formula (X) is coupled with isoquinuclidine toafford the compound of general formula (XXXVI). In the case of that theprotecting group of amine in the compound (XXXVI) is Boc group, theprotecting group is removed by acid such as trifluoroacetic acid or HClin dichloromethane or ethyl acetate to give the compound of generalformula (XI). In the case of Cbz group, the protecting group is removedunder hydrogene —Pd/C in methanol or THF etc. The obtained compound ofgeneral formula (XI) is reacted with sulfonyl chloride or acid chloridein the presence of base such as triethylamine, pyridine etc. indichloromethane or DMF etc. or reacted with the ester compound(R₃CO(CH₂)_(n)R₈) in methanol or benzene etc. or reacted withdiisopropylphosphate (HP(O)(OiPr)₂) in the presence of triethylamine inCCl₄ and obtained the compound of general formula (XII).

-   (F) In the compound of general formula (I), the compound of general    formula (XIII) is prepared by the following reactions.    (wherein R₁, R₂ and A₃ are the same as mentioned above.)

The compound of general formula (XI) is reacetd with diisopropylsquaratein the presence of base such as triethylamine in dicholoromethane or THFetc. to obtain the compound of general formula (XXX), followed by thehydrolysis with aq. HCl in THF or benzene etc. to obtain the compound ofgeneral formula (XIII) (in the case of A₃ is hydrogen). The compound ofgeneral formula XIII, in the case of A₃ is methyl, is obtained by thereaction of the compound of general formula (XXX) with methyl iodide inthe presence of base such as potassium carbonate in DMF or THF to affordthe compound of general formula (XXI), followed by the hydrolysis toobtain the compound of general formula (XIII).

-   (G) In the compound of general formula (I), the compound of general    formula (XVI) is prepared by the following reactions.    (wherein R₁, R₂ and A₁ are the same as mentioned above.)

The compound of general formula (XIV) is reduced by sodium borohydirdeor lithium borohydride in methanol or THF etc. to give the compound ofgeneral formula (XXXII), following by the oxidation such as Swernoxidation etc. to yield the compound of general formula (XV). Theresulting compound of general formula (XV) is converted to thecyanohydrine compound using potassium cyanide or sodium cyanide etc.,followed by the hydrolysis with potassium hydroxide in ethanol to yieldthe compound of general formula (XVI).

-   (H) In the compound of general formula (I), the compound of general    formula (XVII) is prepared by the following reactions.    (wherein A₁, R₁, R₂, R₁₀ and X are the same as mentioned above.)

The compound of general formula (XVI) is reacted with R₁₀—X in thepresence of base such as diisopropylethylamine or sodium hydride indichloromethane or THF etc. to give the compound of general formula(XXXIII), followed by the hydrolysis using aq.NaOH in methanol or THFetc. to yield the compound of general formula (XVII).

-   (I) In the compound of general formula (I), the compound of general    formula (XVIII) is prepared by the following reactions.    (wherein A₁, R₁ and R₂ are the same as mentioned above.)

The compound of general formula (XV) is subjected to Knoevenagelcondensation using dimethyl malonate, followed by the hydrogenation ofthe obtained compound of general formula (XXXIV) to afford the compoundof general formula (XXXV). Furthermore, the compound of general formula(XXXV) is hydrolyzed to obtain the compound of general formula (XVIII).

-   (J) In the compound of general formula (I), the compound of general    formula (XIX) is prepared by the following reactions.    (wherein A₁, R₁ and R₂ are the same as mentioned above.)

The compound of general formula (XV) is reacted withhydroxylamine-o-sulfonic acid in ethanol or methanol or dichloromethaneetc. to obtain the compound of general formula (XIX).

PHARMACOLOGICAL EXPERIMENT

Inhibition of Blood Glucose Increase in Normal Rats

Male Splague-Dawley rats (6 weeks old) were used. After 18 hr fasting,drugs dissolved or suspended in 0.5% methyl cellulose were orallyadministered simultaneously with glucose solution (2 g/kg). Blood wascollected by tail snipping before and 1 hr after oral adminstration.Plasma glucose level was determined by the glucose oxidase method, usinga commercially available kit (Glucose CII Test Wako, Wako, Osaka,Japan). The plasma glucose level after oral adminstration were comparedwith the level before oral administration and percent reduction of risedplasma glucose level relative to vehicle-treated group was calculated asfollows:Percent reduction (%)=(ΔControl−ΔTreated)/(ΔControl)×100Δcontrol: rise in plasma glucose level observed 1 hr after oraladministration in vehicle-treated groupΔTreated: rise in plasma glucose level observed 1 hr after oraladministration in drug-treated group

Compound No. Dose (mg/kg) Reduction percent (%) 1 10 35 10 10 45 11 1043 14 30 32 15 10 35 17 10 48 18 10 82 45 10 59 46 10 88 47 10 26 48 1055 50 10 66 52 10 31

EXAMPLE

The following Example are provided only for the purpose of thepreparation of the compounds and not restricted the disclosed invention.

Reference 1

Synthesis of4(R)-benzyl-3-N-(2-carboxymethyl-3-phenyl-propanoyl)-2-oxazolidione.

(a) Synthesis of 4(R)-benzyl-3-N-(3-phenylpropanoyl)-2-oxazolidinone.

To a solution of hydrocinnamic acid (10.2 g) and Et₃N (10.2 mL) in THF(50 mL) at 0° C. under Ar was slowly added pivaloyl chloride (9.04 g)and allowed to stir at room temperature for 30 min to yield themixanhydride solution. Separately in another flask,4(R)-benzyl-2-oxazolidinone (10 g) was dissolved in THF (80 mL) andcooled to −78° C. under Ar and a 1.6M solution of n-butylithium inn-hexane (35.3 mL) was added to this solution and allowed to stir for 30min. To this solution was added the previously prepared mixanhydride andthe mixture was then allowed to stir for 3 h. The reaction mixture waspoured into saturated NH₄Cl solution (50 mL) and concentrated underreduced pressure. The residue was extracted with ethyl acetate (50 mL×3)and the ethyl acetate layer was washed with brine, dried over Na₂SO₄,filtered and concentrated in vacuo. The objective compound was obtainedas a colorless crystal (13.1 g).

IR(cm⁻¹):3022, 2944, 1785, 1602, 1374, 1203, 1113, 1047, 744, 696.

MS(m/z):309(m⁺), 133, 105, 84(BP), 65, 47.

¹H-NMR(CDCl₃):2.75 (1H, dd), 3.03 (2H, m), 3.20-3.36 (3H, m), 4.17 (2H,m), 4.66 (1H, m), 7.16-7.34 (10H, m).

(b) Synthesis of4(R)-benzyl-3-N-(2-tert-butyloxycarbonylmethyl-3-phenyl-propanoyl)-2-oxazolidione.

A 1.6M solution of n-butylithium in n-hexane (11.2 mL) was added to asolution of diisopropylamine (2.72 mL) in THF (30 mL) at −78° C. Afterstirred for 30 min, the compound (5 g) obtained from the above mentionedstep (a) was added, then tert-butyl bromoacetate was added and thereaction mixture was stirred for 30 min at −78° C., warmed to −20° C.over 1 h and then stirred for 1 h at 0° C. The reaction mixture waspoured into saturated NH₄Cl solution (50 mL) and extracted with ethylacetate (50 mL×3). The ethyl acetate layer was washed with brine, dried(Na₂SO₄), filtered and concentrated in vacuo. The objective compound wasobtained as a colorless crystal (4.01 g).

IR(cm⁻¹):2968, 1782, 1695, 1356, 1290, 1149, 1053, 756, 699.

MS(m/z):423 (m⁺−1), 367, 308, 178, 145, 117, 91, 57(BP).

¹H-NMR(CDCl₃): 1.40 (9H, s), 2.37 (1H, dd), 2.64 (1H, dd), 2.73 (1H,dd), 2.85 (1H, dd), 3.01 (1H, dd), 3.31 (1H, dd), 3.93 (1H, t), 4.08(1H, dd), 4.48-4.53 (2H, m), 7.21-7.36 (10H, m).

(c) Synthesis of4(R)-benzyl-3-N-(2-carboxymethyl-3-phenylpropanoyl)-2-oxazolidinone.

The compound (2.0 g) obtained from the above mentioned step (b) wasdissolved in CH₂Cl₂ (10 ML) and trifluoroacetic acid (3.6 mL) was addedat 0° C. The mixture was stirred for 8 h at room temperature. Thereaction mixture was poured into ice-water (50 mL) and extracted withCHCl₃ (20 mL×3). The CHCl₃ layer was washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo. The objective compound was obtainedas a colorless crystal (1.72 g).

IR(cm⁻¹):3016, 2914, 1776, 1701, 1389, 1206, 1110, 1005, 957, 699.

MS(m/z):367(m⁺), 190, 167, 147, 117, 91 (BP), 57.

¹H-NMR(CDCl₃):2.48 (1H, dd), 2.64 (1H, dd), 2.74 (1H, dd), 2.97 (1H,dd), 3.04 (1H, dd), 3.24 (1H, dd), 3.97 (1H, t), 4.10 (1H, dd),4.49-4.55 (2H, m), 7.22-7.34 (10H, m).

Reference 2

Synthesis ofN-(2-tert-butyloxycarbonylmethyl-3-phenyl-propanoyl-(1S)-(−)-2,10-camphorsultam.

(a) Synthesis of N-(3-phenylpropanoyl)-(1S)-(−)-2,10-camphorsultam.

To a solution of (1S)-(−)-2,10-camphorsultam (1 g) in 15 mL of toluenewas added 55% NaH (223 mg) at 0° C. After stirred for 30 min,hydrocinnamoyl chloride (0.83 mL) was added and the mixture was stirredfor 2 h at room temperature. The reaction mixture was poured intosaturated NH₄Cl solution (80 mL) and extracted with ethyl acetate (50mL×3). The ethyl acetate layer was washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo.

The resulting product was purified by silica gel column chromatographyusing EtoAc:n-hexane (1:10). The objective compound was obtained as acolorless crystal (1.4 g).

IR(cm⁻¹):2944, 1677, 1452, 1320, 1218, 1134, 1113, 1065, 531.

MS(m/z):347(m⁺), 240, 1.05(BP), 79, 55,

¹H-NMR(CDCl₃):0.96 (3H, s), 1.09 (3H, s), 1.34-1.40 (2H, m), 1.85-1.91(3H, m), 2.06 (2H, d), 2.99-3.08 (4H, m), 3.42 (1H, m), 3.48 (1H, m),3.86 (1H, t), 7.18-7.29 (5H, m).

(b) Synthesis ofN-(2-tert-butyloxycarbonylmethyl-3-phenylpropanoyl-(1S)-(−)-2,10-camphorsultam.

The compound (500 mg) prepared by the above mentioned step (a) wasdissolved in THF (5 mL) and 1.6M solution of n-butyllithium in n-hexane(1.06 mL) was added at −78° C. and stirred for 30 min.Tert-butylbromoacetate (0.23 mL) and tetrabutylammonium iodide in HMPA(1 mL) was added to the mixture and the reaction mixture was stirred for3 h at −78° C. The reaction mixture was poured into saturated NH₄Clsolution (50 mL) and extracted with ethyl acetate (50 mL×3). The ethylacetate layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo.

The resulting product was purified by silica gel column chromatographyusing EtoAc:n-hexane (1:2). The objective compound was obtained as acolorless crystal (525 mg).

IR(cm⁻¹):2962, 1725, 1677, 1326, 1284, 1152, 765, 531.

MS(m/z):461 (m⁺), 405, 346, 256, 216(BP), 162, 115, 55.

¹H-NMR(CDCl₃):0.97 (3H, s), 1.25 (3H, s), 1.32-1.56 (2H, m), 1.38 (9H,s), 1.88 (3H, m), 2.03 (1H, dd), 2.15 (1H, m), 2.34 (1H, dd), 2.55 (1H,dd), 2.66 (1H, dd), 3.32 (1H, dd), 3.46 (1H, m), 3.53 (1H, m), 3.61 (1H,m), 3.92 (1H, dd), 7.19-7.30 (5H, m).

Example 1

Synthesis of (2S)-2-benzyl-4-(isoguinuclidin-2-yl)-4-oxo-butanoic acid(compound 1)

(a) Synthesis of4(R)-benzyl-3-N-(2-isoguinuclidinecarbonylmethyl-3-phenyl-propanoyl)-2-oxazolidione.

The compound (500 mL) obtained from the above mentioned Reference 1 wasdissolved in THF/DMF (3/1) (4 mL) and isoquinuclidin hydrochloride (241mg), DEPC (0.166 mL) and Et₃N (0.57 mL) was added to this solution at 0°C. The mixture was stirred at room temperature for 30 min. The reactionmixture was poured into saturated NaHCO₃ (50 mL) and extracted withethyl acetate (50 mL×3). The ethyl acetate layer was washed withsaturated citric acid, brine, dried (Na₂SO₄), filtered and concentratedin vacuo. The objective compound was obtained a colorless crystal (269mg).

IR(cm⁻¹):3412, 2988, 1766, 1636, 1440, 1378, 1252, 1196, 1004, 746, 508.

MS(m/z):460(m⁺−1), 284, 256, 207, 178, 153, 117, 91 (BP), 55.

¹H-NMR(CDCl₃): 1.58-1.95 (9H, m), 2.34 and 2.41 (total 1H, each dd),2.64-3.07 (4H, m), 3.28-3.46 (2H, m), 3.66 and 4.39 (total 1H, each s),3.85 and 3.92 (total 1H, each t), 4.02-4.28 (2H, m), 4.47-4.66 (2H, m),7.18-7.34 (10H, m).

(b) Synthesis of (2S)-2-benzyl-4-(isoquinuclidin-2-yl)-4-oxo-butanoicacid (compound 1).

The compound (143 mg) obtained from the above mentioned Example 1 (a)was dissolved in THF/DMF (3/1) (4 mL) and cooled to 0° C. and 30% H₂O₂(0.16 mL) was added to the solution with stirring for 5 min. Afteraddition of LiOH.H₂O (26 mg), the mixture was stirred for 2 h at roomtemperature, then 10% Na₂SO₃ (10 ML) was added drop wise. After stirring15 min, the solvent was concentrated in vacuo.

The resulting residue was extracted with ethyl acetate (50 mL×3). Theethyl acetate layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The resulting product was purified by silica gelcolumn chromatography using CHCl₃:EtoAc (5:1). The objective compoundwas obtained as a colorless crystal (80 mg).

IR(cm⁻¹):2926, 2860, 1725, 1590, 1452, 1245, 1176, 732, 699.

MS(m/z):301(m⁺), 257, 190, 153(BP), 117, 97, 82, 57.

¹H-NMR(CDCl₃): 1.54-1.85 (9H, m), 2.38 (1H, dd), 2.47 (1H, m), 2.76 (1H,m), 3.01 (1H, m), 3.11 (1H, m), 3.32 (1H, dd), 3.41 and 4.52 (total 2H,each s), 7.71-7.33 (5H, m), 13.18 (1H, br, s)

Example 2

Synthesis of (2S)-2-benzyl-4-(isoquinuclidin-2-yl)-4-oxo-butanoic acidphenylester (compound 15).

The compound (100 mg) obtained from the above mentioned Example 1 wasdissolved in CH₂Cl₂ (5 mL) and phenol (94 mg), WSCDI (64 mg)dimethylaminopyridine (4 mg) was added to the solution at 0° C. Thereaction mixture was stirred for 2 h at room temperature. The reactionmixture was poured into saturated citric acid (50 mL) and extracted withethyl acetate (50 mL×3). The ethyl acetate layer was washed brine, dried(Na₂SO₄), filtered and concentrated in vacuo. The resulting product waspurified by silica gel column chromatography using n-hexane:EtoAc (5:1).The objective compound was obtained as a colorless crystal (68 mg).

IR(cm⁻¹):3412, 2932, 1758, 1632, 1434, 1374, 1191, 1086, 921, 750.

MS(m/z):284(m⁺−93,BP), 190, 153, 124, 95, 55.

¹H-NMR(CDCl₃):1.62-1.95 (9H, m), 2.40 and 2.48 (total 1H, each dd),2.70-2.78 (total 1H, each dd), 2.98 (1H, m), 3.14 (1H, m), 3.32-3.50(3H, m), 3.69 and 4.50 (total 1H, each s), 6.95-7.34 (10H, m).

Example 3

Synthesis of (2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanoic acidmethyl ester (compound 13)

The compound (145 mg) obtained from the above mentioned Example 1 wasdissolved in a mixture of MeOH (5 mL) and conc.H2SO₄ (1 mL) and themixture was reflux for 1 h. The reaction mixture was concentrated invacuo. The resulting product was poured into saturated NaHCO₃ (30 mL)and extracted with ethyl acetate (50 mL×3). The ethyl acetate layer waswashed brine, dried (Na₂SO₄), filtered and concentrated in vacuo. Theresulting product was purified by silica gel column chromatography usingn-hexane:EtoAc (5:1). The objective compound was obtained as a colorlessoil (149 mg).

IR(cm⁻¹):2926, 1728, 1626, 1434, 1371, 1164, 1098, 990, 747.

MS(m/z):315(m⁺), 284, 173, 153, 117, 84(BP), 47.

¹H-NMR(CDCl₃):1.62-1.94 (9H, m), 2.24 and 2.32 (total 1H, each dd),2.58-2.67 (total 1H, each dd), 2.81 (1H, m), 3.02 (1H, m), 3.24-3.42(3H, m), 3.65 and 3.66 (total 3H, each s), 3.66 and 4.46 (total 1H, eachm), 7.15-7.30 (5H, m).

Example 4

Synthesis ofN-[(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanoyl]4-aminopyridine(compound 2).

The compound (87 mg) obtained from the above mentioned Example 1 wasdissolved in CH₂Cl₂ (3 mL) and HOBt (53 mg), WSCDI (67 mg) andN-methylmorpholine (0.04 mL) was added to the solution at 0° C. Themixture was stirred for 1 h at room temperature, N-methylmorpholine(0.05 mL) and 4-methylaminopyridine (41 mg) was added to the mixture.The reaction mixture was stirred for 8 h at room temperature. Thereaction mixture was poured into saturated NaCl (50 mL) and extractedwith ethyl acetate (50 mL×3). The ethyl acetate layer was washed brine,dried (Na₂SO₄), filtered and concentrated in vacuo. The resultingproduct was purified by silica gel column chromatography usingCHCl₃:MeOH (50:1). The objective compound was obtained as a colorlesscrystal (10 mg).

IR(cm⁻¹):3400, 2926, 1692, 1605, 1527, 1455, 1170, 966, 822, 750.

MS(m/z):377(m⁺), 284, 256, 225, 190, 153, 119, 91, 71, 52(BP).

¹H-NMR(CDCl₃): 1.58-1.71 (8H, m), 1.93 (1H, s), 2.35 (1H, ddd),2.71-2.86 (2H, m), 3.07 (1H, m), 3.23 (1H, m), 3.31-3.49 (2H, m), 3.76and 4.38 (total 1H, each s), 7.17-7.36 (5H, m), 7.49 (2H, d), 7.66 and7.77 (total 1H, each d), 8.33 (2H, d).

Example 5

Synthesis of S-(o-methoxycarbonyl)phenyl(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxothiobutanoate (compound 50).

The compound (200 mg) obtained from the above mentioned Example 1 wasdissolved in CH₂Cl₂ (3 mL) and o-methoxycarbonyl-thiophenol (167 mg),WSCDI (191 mg) and dimethylamino-pyridine (16 mg) was added to thesolution at 0° C. The mixture was stirred at room temperature for 3 hand the reaction mixture was poured into saturated NH₄Cl (50 mL) andextracted with ethyl acetate (50 mL×3). The ethyl acetate layer waswashed brine, dried (Na₂SO₄), filtered and concentrated in vacuo. Theresulting product was purified by silica gel column chromatography usingCHCl₃:MeOH (20:1). The objective compound was obtained as a yellow oil(132 mg).

IR(cm⁻¹):2926, 1725, 1632, 1440, 1290, 1254, 933, 747, 699.

ESI-MS:(m⁺H)+m/z 284.

¹H-NMR(CDCl₃): 1.53-1.93 (9H, m), 2.32 (1H, m), 2.66-2.86 (2H, m),3.15-3.39 (3.5H, m), 3.65 (1H, m), 3.85 (3H, s), 4.47 (0.5H, s),7.15-7.90 (9H, m).

Example 6

Synthesis of o-ethoxycarbonylphenyl(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanoate (compound 48)

It was prepared following the Example 2, starting from the compound (200mg) obtained from the above mentioned Example 1 and ethyl salicylate(0.1 mL). The resulting product was purified by silica gel columnchromatography using n-hexane: EtoAc (2:1). The objective compound wasobtained as a colorless oil (250 mg).

IR(cm⁻¹):2926, 1722, 1626, 1443, 1293, 1254, 1134, 1080, 750.

MS(m/z):450(m⁺), 284, 190, 153, 120(BP), 92, 65.

¹H-NMR(CDCl₃): 10.35 (3H, m), 1.59-1.95 (9H, m), 2.43 (1H, m), 2.67 (1H,m), 2.99 (1H, m), 3.28-3.44 (3H, m), 3.54 (1H, m), 3.69 and 4.51 (total1H, each s), 4.31 (2H, m), 7.09 (1H, m), 7.21-7.34 (6H, m), 7.51 (1H,m), 7.96 (1H, m)

Example 7

Synthesis of o-methoxycarbonylphenyl(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanoate (compound 46)

The compound (180 mg) obtained from the above mentioned Example 2 wasreacted with methyl salicylate (0.08 mL) by the same procedure describedin Example 1.

The resulting product was purified by silica gel column chromatographyusing n-hexane: EtoAc (2:1). The objective compound was obtained as acolorless oil (220 mg).

IR(cm⁻¹):2932, 172, 1629, 1437, 1296, 1257, 1134, 1083, 747.

MS(m/z):435(m⁺), 284, 242, 192, 153(BP), 120, 91, 55.

¹H-NMR(CDCl₃): 1.62-1.94 (9H, m), 2.41 (1H, m), 2.76 (1H, m), 2.98 (1H,m), 3.28-3.44 (3H, m), 3.56 (1H, m), 3.69 and 4.50 (total 1H, each s),3.83 (3H, m), 7.08 (1H, m), 7.22-7.34 (6H, m), 7.52 (1H, t), 7.97 (1H,d).

Example 8

Synthesis of p-methoxyphenyl(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butylate (compound 17).

The compound (1.0 g) obtained from the above mentioned Example 2 wasreacted with p-methoxy phenol by the same procedure described in Example1 (1.24 g).

The resulting product was purified by silica gel column chromatographyusing n-hexane: EtoAc (2:1). The objective compound was obtained as acolorless oil (1.21 g)

IR(cm⁻¹):2932, 1746, 1626, 1440, 1299, 1248, 1137, 1029, 750.

MS(m/z):408(m⁺+1), 284(BP), 256, 190, 145, 117, 91, 55.

¹H-NMR(CDCl₃):1.60-1.95 (9H, m), 2.39 and 2.46 (total 1H, each dd), 2.73(1H, m), 2.97 (1H, m), 3.12 (1H, m), 3.40 (3H, m), 3.69 and 4.49 (total1H, each s), 3.77 (3H, s), 6.85 (4H, m), 7.29 (10H, m).

Example 9

Synthesis of p-hydroxy phenyl(2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butyrate (compound 18)

The compound (300 mg) obtained from the above mentioned Example 2 wasreacted with p-benzyloxyphenol (598 mg) by the same procedure describedin Example 1. The resulting product was dissolved in THF (5 mL) and 5%Pd on carbon (100 mg) was added. The reaction mixture was stirred for 5h under a hydrogen atmosphere, filtered and concentrated in vacuo. Theresulting product was purified by silica gel column chromatography usingn-hexane:EtoAc (2:1). The objective compound was obtained as a colorlessoil (350 mg).

IR(cm⁻¹):3266, 2938, 1749, 1605, 1446, 1374, 1245, 1188, 1002, 774.

MS(m/z):393(m⁺), 258, 187, 149(BP), 125, 86, 47.

¹H-NMR(CDCl₃): 1.61-1.95 (9H, m), 2.40 (1H, m), 2.75 (1H, m), 2.94 (1H,m), 3.17 (1H, m), 3.29 (3H, m), 3.69 and 4.46 (total 1H, each s), 6.73(4H, m), 7.28 (10H, m).

Reference 3

Synthesis of (2S)-2-benzyl-4(isoquinuclidine-2-yl)-4-oxo-butanal.

(a) Synthesis of (2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanol.

The compound (1.08 g) obtained from the above mentioned Example 3 wasdissolved in Ether/THF (10:1) (11 mL) and LiBH₄ (75 mg) was added to thesolution at 0° C. After stirred for 30 min at 0° C., the reactionmixture was poured into 10% HCl (30 mL) and extracted with ethyl acetate(50 mL×3). The ethyl acetate layer was washed with brine, dried(Na₂SO₄), filtered and concentrated in vacuo. The resulting product waspurified by silica gel column chromatography using CHCl₃:MeOH (20:1).The objective compound was obtained as a colorless crystal (778 mg).

IR(cm¹⁻): 3376, 2926, 2860, 1605, 1449, 1248, 1032, 741, 699.

MS(m/z):287(m⁺), 262, 153, 118, 83(BP), 47.

¹H-NMR(CDCl₃): 1.55-1.94 (9H, m), 2.26-2.45 (3H, m), 2.54 (1H, m), 2.75(1H, m), 3.21 (1H, m), 3.39 (1H, s), 3.47 and 4.50 (total 1H, each s),3.54 (1H, m), 3.72 (1H, m), 7.17-7.30 (5H, m).

(b) Synthesis of (2S)-2-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanal.

Oxalyl chloride (2M, CH₂Cl₂, 1.9 mL) was dissolved in CH₂CL2 (3 mL) at−60° C. under Ar and DMSO (0.6 mL) was added to the solution. Afterstirred for 20 min, the compound (587 mg) obtained from the abovementioned Example 3 (a) in CH₂Cl₂ (7 mL) was added to the mixture. Afterstirred for 1.5 h, NEt₃ (1.7 mL) was added and allowed the stir for 1 h.The reaction mixture was poured into H₂O (50 mL) and extracted withether (500 mL×3). Ether layer was washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo. The resulting product was purifiedby silica gel column chromatography using ether. The objective compoundwas obtained as a yellow oil (580 mg).

IR(cm⁻¹):2926, 2854, 1722, 1626, 1440, 1248, 738, 699.

MS(m/z):285(m⁺), 153, 124, 86(BP), 58.

¹H-NMR(CDCl₃): 1.58-1.95 (9H, m), 2.34 (1H, m), 2.61 (1H, m), 2.79 (1H,m), 3.11 (1H, m), 3.24 (1H, m), 3.41 (1H, m), 3.64 and 4.46 (total 1H,each s), 7.17-7.32 (5H, m), 9.88 (1H, d).

Example 10

Synthesis of(4S)-4-benzyl-2-carboxy-6-(isoquinuclidine-2-yl)-6-oxo-2-hexanoic acid(compound 40).

(a) Synthesis of(4S)4-benzyl-2-methoxycarbonyl-6-(isoquinuclidine-2-yl)-6-oxo-hexenAcid.

The compound (100 mg) obtained from the above mentioned Example 2 wasdissolved in tolune:cyclohexane (1:1) (4 mL) and diethylmalonate (0.048mL), benzoic acid (1.5 mg), piperidine (0.002 mL) and MS 4 Å (50 mg)were added to the solution. The mixture was refluxed for 6 h and pouredinto saturated citric acid (50 mL) and extracted with ethyl acetate. Theethyl acetate layer was washed with saturated NaHCO₃ and brine, dried(Na₂SO₄), filtered and concentrated in vacuo. The resulting product waspurified by silica gel column chromatography using EtoAc:n-hexane (1:2).The objective compound was obtained as a yellow oil (128 mg).

IR(cm⁻¹):2926, 1740, 1629, 1440, 1248, 1011, 747.

MS(m/z):399(m⁺), 335, 268, 185, 153, 124, 95(BP), 59.

¹H-NMR(CDCl₃): 1.54-1.94 (9H, m), 2.32 (1H, m), 2.80-3.59 (5H, m), 3.75(6H, m), 4.37-4.53 (2H, m), 5.68-5.89 (1H, m), 6.99-7.29 (5H, m).

(b) Synthesis of(4S)-4-benzyl-2-methoxycarbonyl-6-(isoquinuclidine-2-yl)-6-oxo-2-hexanoicAcid Methyl Ester.

A mixture of the compound (128 mg) obtained from the above mentionedExample 10 (a) in MeOH (5 mL) and 10% Pd on carbon (50 mg) was stirredfor 12 h under a hydrogen atmosphere, filtered and concentrated invacuo. The objective compound was obtained as a colorless oil (128 mg).

IR(cm⁻¹):2932, 1734, 1629, 1437, 1248, 1002, 744.

MS(m/z):401 (m⁺), 370, 227, 153(BP), 124, 82, 54.

¹H-NMR(CDCl₃): 1.62-2.19 (12H, m), 2.68 (4H, m), 3.37-3.59 (3.5H, m),3.72 (6H, m), 4.51 (0.5H, m), 7.01-7.29 (5H, m).

(c) Synthesis of(4S)-4-benzyl-2-carboxy-6-(isoquinuclidine-2-yl)-6-oxo-2-hexanoic acid(compound 40).

To a solution the compound (128 mg) obtained from the above mentionedExample 10 (b) in MeOH:THF (2:1) (3 mL) was added 10% NaOH (1 mL) at 0°C. The mixture was stirred for 3 h at room temperature and treated withsaturated citric acid to adjust the pH 7. The reaction mixture wasextracted with CHCl₃ (50 mL×3). The CHCl₃ layer was washed with brine,dried (Na₂SO₄), filtered and concentrated in vacuo. The objectivecompound was obtained as a colorless crystal (96 mg).

IR(cm⁻¹):3406, 2932, 1707, 1563, 1455, 1212, 744.

ESI-MS:(m+H)+m/z 374

¹H-NMR(CDCl₃): 1.55-1.98 (10H, m), 2.04-2.38 (2H, m), 2.48-2.61 (3H, m),2.78 (1H, m), 3.08 and 3.33 (total 1H, each d), 3.39 (2H, m), 3.56 and4.50 (total 1H, each s), 7.12-7.33 (5H, m).

Example 11

Synthesis ofN-(3-hydroxy-3-cyclobutene-1,2-dione-4-yl)-(1S)-[2-(isoquinuclidine-2-yl)-2-oxo-ethyl]phenylethylamine (compound 51).

(a) Synthesis ofN-(3-isopropoxy-3-cyclobutene-1,2-dione-4-yl)-(1S)-[2-(isoquinuclidine-2-yl)-2-oxo-ethyl]phenylethylamine

To a solution of (1S)-[2-(isoquinuclidine-2-yl)-2-oxo-ethyl]phenyl amine(600 mg) in CH₂Cl₂ (8 mL) were added Et₃N (0.37 mL) and Diisopropylsquarate (437 mg). The reaction mixture was refluxed for 6 h, pouredinto H₂O (50 mL) and extracted with ethyl acetate (50 mL×3). The ethylacetate layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The resulting product was purified by silica gelcolumn chromatography using CHCl₃:EtoAc (1:1). The objective compoundwas obtained as a colorless oil (903 mg).

IR(cm⁻¹):2908, 1803, 1710, 1557, 1377, 1239, 1086, 765.

MS(m/z):410(m⁺), 319, 283, 256, 213, 181, 138(BP), 95, 67.

¹H-NMR(CDCl₃):1.40 (6H, d), 1.54-2.02 (9H, m), 2.43 and 2.53 (total 2H,each m), 2.95-3.25 (3H, m), 3.46 and 4.53 (total 1H, each s), 3.47 (1H,m), 4.24 and 4.71 (total 1H, each m), 5.34 (1H, m), 7.16-7.31 (5H, m),7.42 and 7.52 (total 1H, each m).

(b) Synthesis ofN-(3-hydroxy-3-cyclobutene-1,2-dione-4-yl)-(1S)-[2-(isoquinuclidine-2-yl)-2-oxo-ethyl]phenylethylamine (compound 51).

A mixture of the compound (450 mg) obtained from the above mentionedprocedure Example 11 (a) in THF (20 mL) and 10% HCl (5 mL) was refluxedfor 12 h. The reaction mixture was treated with 10% NaOH to adjust thepH 10 and was washed with ethyl acetate. The basic layer was treatedwith 10% HCl to adjust the ph7 and extracted with CHCl₃ (50 mL×3). TheCHCl₃ layer was washed with brine and dried (Na₂SO₄), filtered andconcentrated in vacuo. The resulting product was purified by silica gelcolumn chromatography using CHCl₃:MeOH (10:1). The objective compoundwas obtained as a colorless crystal (342 mg).

IR(cm⁻¹):3244, 2926, 1800, 1584, 1422, 1245, 744.

ESI-MS:(m⁺H)⁺m/z 369.

¹H-NMR(CDCl₃): 1.67-2.02 (9H, m), 2.53 (1H, d), 2.61 (1H, d), 2.96-3.47(4H, m), 3.54 and 4.44 (total 1H, each s), 4.68 (1H, m), 7.19-7.32 (5H,m), 8.24 (1H, m).

Example 12

Synthesis ofN-(3-hydroxy-3-cyclobutene-1,2-dione-4-yl)-N-methyl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]-phenylethylamine. (compound 52)

(a) Synthesis ofN-(isopropoxy-3-cyclobutene-1,2-dione-4-yl)-N-methyl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]phenylethylamine.

A mixture of the compound (500 mg) obtained from the above mentionedExample 11 (a) was dissolved in DMF (15 mL) and CH₃I (0.1 mL), K₂CO₃(168 mg) was added. The mixture was stirred at room temperature for 12h. The reaction mixture was poured into H₂O (50 mL) and extracted withethyl acetate (50 mL×3), the ethyl acetate layer was washed with brine,dried (Na₂SO₄), filtered and concentrated in vacuo. The objectivecompound was obtained as a yellow oil (430 mg).

IR(cm⁻¹):2926, 1794, 1698, 1590, 1449, 1386, 1095, 747.

MS(m/z):424(m⁺), 333, 291, 256, 230, 195(BP), 95, 55.

¹H-NMR(CDCl₃): 1.36-1.48 (6H, m), 1.59-1.99 (9H, m), 2.50-3.05 (4H, m),3.05 and 3.24 (total 3H, each d), 3.43 (2H, m), 3.66 and 4.46 (total 1H,each m), 4.63 (1H, m), 5.40 (1H, m), 7.16-7.32 (5H, m).

(b) Synthesis ofN-(3-hydroxy-3-cyclobutene-1,2-dione-4-yl)-N-methyl-(1S)-[2-(isoquinuclidine-2yl)-2-oxo-ethyl]phenylethylamine (compound 52)

A mixture of the compound (430 mg) obtained from the above mentionedExample 12 (a) in THF (5 mL) and 10% HCl (5 mL) was refluxed for 3 h.The reaction mixture was poured into H₂O (50 mL) and extracted withCHCl₃.(50 mg×3) the CHCl₃ layer was washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo. The resulting product was purifiedby silica gel column chromatography using CHCl₃:MeOH (10:1). Theobjective compound was obtained as a colorless crystal (386 mg).

IR(cm⁻¹):3406, 2926, 1797, 1578, 1452, 1245, 699.

ESI-MS:(m+H)⁺m/z 383.

¹H-NMR(CDCl₃): 1.64-1.96 (9H, m), 2.63 (1H, m), 2.83-3.08 (3H, m), 3.22(3H, d), 3.40 (2H, m), 3.67 and 4.45 (total 1H, each s), 4.68 (1H, m),5.98 (1H, s), 7.19-7.32 (5H, m).

Example 13

Synthesis of4-(isoquinuclidin-2-yl)-4-oxo-(2S)-benzyl-butylaldehydeoxime-o-sulfonicacid (compound 53)

Hydroxylamine-o-sulfonic acid (333 mg) was added at room temperature ofto a solution the compound (700 mg) obtained from the above mentionedReference 2 in EtOH (10 mL) and stirred for 3 h. The solvent wasconcentrated in vacuo. The objective compound was obtained as acolorless crystal (275 mg).

IR(cm⁻¹):3418, 3100, 1665, 1440, 1398, 1206, 1047, 624.

ESI-MS:(m+H)⁺m/z 381

¹H-NMR(DMSO): 1.66-1.98 (9H, m), 2.32-2.62 (2H, m), 2.85-3.00 (2H, m),3.10-3.22 (1H, m), 3.33-3.59 (2H, m), 3.80 and 4.40 (total 1H, each m),6.98 and 7.56 (total 1H, each m), 7.30-7.42 (5H, m), 9.40 (1H, s).

Example 14

Synthesis of(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]-N-trifluoromethanesulfonyl-phenylethylamine (compound 16)

(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]-phenyl ethylamine (300 mg)was dissolved in CH₂Cl₂ (5 mL) and then Et₃N (0.23 mL),trifluoromethansulfonic anhydride (0.28 mL) was added at −78° C. Afterstirring 2 h, MeOH (1 mL) and 10% NaOH (0.3 mL) was added and stirredfor 10 min. The reaction mixture was poured into H₂O (50 mL) andextracted with ethyl acetate (50 mL×3), the ethyl acetate layer waswashed with brine, dried (Na₂SO₄), filtered and concentrated in vacuo.The resulting product was purified by silica gel column chromatographyusing EtoAc:n-hexane (1:1). The objective compound was obtained as acolorless crystal (115 mg).

IR(cm⁻¹):3052, 2938, 1602, 1461, 1374, 1230, 1071, 750.

MS(m/z):404(m⁺), 313, 255, 138(BP), 91, 55.

¹H-NMR(CDCl₃): 1.58-1.90 (9H, m), 2.30 (1H, d), 2.41 (1H, d), 2.94-3.21(3H, m), 3.41 and 4.54 (total 1H, each s), 3.46 (1H, m), 3.94-4.01 (1H,m), 7.13-7.33 (5H, m), 7.56 and 7.71 (total 1H, each d).

Example 15

Synthesis ofN-[(2S)-benzyl-4-(isoquinuclidine-2-yl)-4-oxo-butanoyl]-(3,5-difluoro-4-hydroxy)aniline (compound 38)

Oxalyl chloride (2M CH₂Cl₂) (0.38 mL) was dissolved in CH₂Cl (2 mL)/DMF(0.07 mL) at −15° C. and stirred for 30 min. The mixture wasconcentrated in vacuo and CH₂Cl₂ (2 mL) was added at 0° C. The compound(200 mg) obtained from the above mentioned Example 1 was slowly added toit and the mixture was stirred for 30 min. In a separate flask,3,5-difluoro-4-hydroxyaniline. HCl (241 mg) was dissolved in CH₂Cl₂ (4mL) and then Et₃N (0.42 mL) was added at 0° C. After stirring 15 min,above the reaction mixture was added to this solution at 0° C. over 5min. The mixture was then allowed to stir for 30 min. The reactionmixture was poured into H₂O (50 mL) and extracted with ethyl acetate.The organic layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The resulting product was purified by silica gelcolumn chromatography using CHCl₃:MeOH (5:1). The objective compound wasobtained as a yellow crystal (100 mg).

IR(cm⁻¹):3280, 2932, 1611, 1437, 1350, 1236, 1017, 699.

MS(m/z):428(m⁺), 284, 190, 145, 111, 84, 57(BP).

¹H-NMR(CDCl₃): 1.55-1.93 (9H, m), 2.36 (1H, m), 2.77 (2H, m), 3.10-3.42(4H, m), 3.68 and 4.44 (total 1H, each s), 6.26 (1H, s), 7.00 (2H, m),7.16-7.27 (5H, m), 8.80 and 8.95 (total 1H, each s).

Example 16

Synthesis ofN-Diisopropoxyphosphoryl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]-phenylethylamine(compound 31)

To a solution of (1S)-[2-(isoquinuclidine-2-yl)-2-oxo-ethyl]phenyl amine(300 mg) in CCl₄ (3.5 mL) were added Et₃N (0.31 mL) and diisopropylphosphate (0.13 mL) at 0° C. After stirring 12 h, the reaction mixturewas poured into H₂O (50 mL) and extracted with ethyl acetate (50 mL×3).The resulting product was purified by silica gel column chromatographyusing CHCl₃:MeOH (50:1). The objective compound was obtained as acolorless oil (360 mg).

IR(cm⁻¹):3208, 2920, 1626, 1422, 1383, 1245, 1101, 744.

MS(m/z):436(m⁺), 345, 261, 138(BP), 91, 47.

¹H-NMR(CDCl₃): 1.23-1.39 (12H, m), 1.63-2.00 (9H, m), 2.28 (1H, d), 2.38(1H, d), 2.94-3.22 (3H, m), 3.43 (1H, m), 3.54 and 4.55 (total 1H, eachs), 3.77 (1H, m), 4.06 and 4.78 (total 1H, each m), 7.18-7.29 (5H, m).

Example 17

Synthesis ofN-Carboxymethylsulfonyl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]phenylethylamine (compound 20)

(a) Synthesis ofN-ethoxycarbonylmethylslufonyl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]phenylethylamine

A mixture of (1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]phenyl ethylamine(300 mg) and Et₃N (0.92 mL) in CH₂Cl₂ (2 mL) was cooled to 0° C. andchrolosulfonylacetic acid ethyl ester (494 mL) was slowly added to themixture. After stirring 4 h, the reaction mixture was poured intosaturated NH₄Cl (50 mL) and extracted with ethyl acetate (50 mL×3). Theethyl acetate layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The resulting product was purified by silica gelcolumn chromatography using CH₃Cl₃:MeOH (50:1). The objective compoundwas obtained as a colorless oil (519 mg).

MS(m/z):423(m⁺), 377, 331, 255, 138(BP), 91, 55.

(b) Synthesis ofN-Carboxymethylslufonyl-(1S)-[2-(isoquinuclidin-2-yl)-2-oxo-ethyl]phenyl-ethylamine(compound 20)

A mixture of the compound (494 mg) obtained from the above mentionedExample 17 (a) and saturated Na₂CO₃ (3 mL) in EtOH (5 mL) was stirredfor 12 h at room temperature. The reaction mixture was poured intosaturated citric acid (50 mL) and extracted with CHCl₃ (50 mL×3). TheCHCl₃ layer was washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The objective compound was obtained as acolorless crystal (121 mg).

IR(cm⁻¹):3400, 3298, 1692, 1482, 1332, 1221, 1074, 618.

MS(m/z):335(m⁺−59), 313, 255, 138(BP), 91, 55.

¹H-NMR(CD₃OD): 1.67-1.93 (9H, m), 2.36-2.61 (2H, m), 2.91 (2H, m),3.36-3.42 (2H, m), 3.46-3.62 (2H, m), 3.64 and 4.37 (total 1H, each s),3.65-3.84 (1H, m), 4.06-4.16 (1H, m), 7.23-7.32 (5H, m).

Example 18

Synthesis ofN-[(2S)-2-benzyl-4-(isoquinuclidin-2-yl)-4-oxo-butanoyl]-2-aminothiazole(compound 3)

To a solution of the compound (80 mg) obtained from the above mentionedExample 1 in CH₂Cl₂ (3 mL) were added HOBt * H₂O (49 mg), WSCDI (61 mg)and N-methylmorpholine (0.03 mL). The mixture was stirred at 0° C. for 1h and N-methylmorpholine (0.04 mL) and 2-aminothiazole (40 mg) was addedto the mixture. After stirring for 2 h, the reaction mixture was pouredinto saturated NaCl (50 mL) and extracted with ethyl acetate (50 mL×3).The ethyl acetate layer was washed with brine, dried (Na₂SO₄), filteredand concentrated in vacuo. The resulting product was purified by silicagel column chromatography using EtoAc. The objective compound wasobtained as a colorless crystal (102 mg).

IR(cm⁻¹):3424, 2926, 1683, 1608, 1548, 1452, 1170, 915, 867, 699.

MS(m/z):383(m⁺−1), 285(BP), 256, 231, 190, 153, 127, 95, 67.

¹H-NMR(CDCl₃):0.87-1.91 (9H, m), 2.41-2.87 (3H, m), 3.11-3.27 (2H, m),3.38 (2H, m), 3.67 and 4.48 (total 1H, each s), 6.91 (1H, d), 7.14-7.34(5H, m), 7.46 (1H, d), 11.7 (1H, s).

Example 19

Synthesis of(4S)-4-benzyl-2-hydroxy-5-(isoquinuclidin-2-yl)-5-oxo-pentanoic acid(compound 41)

To a solution of the compound (730 mg) obtained from the above mentionedReference 2 in CH₂Cl₂ (8.4 mL) was added aq NaHSO₃ (1.76 g) (6 mL) at 0°C. After stirring for 1 h, NaCN (691 mg) was added to the mixture andthe mixture was stirred for 14 h at room temperature. The reactionmixture was poured into H₂O(50 mL) and extracted with ethyl acetate (5mL×3). The ethyl acetate layer was washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo.

The residue was dissolved in EtOH (10 mL) and 10% KOH (5 mL) and themixture was refluxed for 4 h. After concentrated in vacuo, the resultingresidue was treated with 10% HCl to adjust the pH 2. The mixture wasextracted with ethyl acetate (50 mL×3) and the ethyl acetate layer waswashed with brine dried (Na₂SO₄), filtered and concentrated in vacuo.The resulting product was purified by silica gel column chromatographyusing CH₃Cl₃:MeOH (8:1). The objective compound was obtained as acolorless crystal (311 mg).

MS(m/z):311(m⁺), 286, 256, 242, 153, 117, 91 (BP).

¹H-NMR(CDCl₃): 1.39-1.82 (11H, m), 2.23-3.70 (8.5H, m), 4.03-4.38 (1H,m), 4.42-4.50 (0.5H, m), 7.14-7.31 (6H, m)

Example 20

Synthesis of(4S)-4-benzyl-2-methoxymethyloxy-5-(isoquinuclidine-2-yl)-5-oxo-pentanoicacid (compound 43)

To a solution of the compound (150 mg) was obtained from the abovementioned Example 19 was dissolved in CH₂Cl₂ (8.4 mL) were added at 0°C. diisopropylamine (0.24 mL) and methoxymethyl chloride (0.1 mL). Afterstirring for 14 h, the reaction mixture was poured into H₂O (50 mL) andextracted with ethyl acetate (50 mL×3). The ethyl acetate layer waswashed with brine, dried (Na₂SO₄), filtered and concentrated in vacuo.The resulting product was dissolved in MeOH (10 mL) and 10% KOH (5 mL)was added and stirred at room temperature for 2 h. The reaction mixturewas poured into 10% critic acid (50 mL) and extracted with ethyl acetate(50 mL×3). The ethyl acetate layer was washed with brine, dried(Na₂SO₄), filtered and concentrated in vacuo. The resulting product waspurified by silica gel column chromatography using CHCl₃:MeOH (8:1). Theobjective compound was obtained as a yellow crystal (63 mg).

IR(cm⁻¹):3540, 2938, 2860, 1725, 1596, 1452, 1215.

MS(m/z):375(m⁺), 330, 301, 256, 153, 117, 91(BP).

¹H-NMR(CDCl₃):1.37-1.96(10H, m), 2.08-2.75 (3H, m), 2.80-3.66 (7.5H, m)

EFFECT OF THE INVENTION

The novel isoquinuclidine derivatives or the pharmaceutically acceptablesalts in this invention has a potent blood glucose lowering activity anda safety, and it expect that useful as therapeutic and preventive agentsof diabetes or diabetic complications.

1. A compound of formula (I) or a pharmaceutically acceptable salt,

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-Ph, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—, R₃ represents —COOH,—COOR₄, —COSR₄, —CONHR₅, —NHR₆, —P(O) (OPri)₂, —CH(R₉)COOH,—CH₂CH(COOH)₂, —SO₃H, or a following formula:

wherein, R₄ represents lower alkyl, non-substituted phenyl group, orphenyl group which is substituted with lower alkyl, lower alkoxy,hydroxy, methoxycarbonyl, ethoxycarbonyl, trifluoromethanesulfoneamideor halogen, R₅ represents pyridyl, thiazolyl, non-substituted phenylgroup, or phenyl group which is substituted with lower alkyl, loweralkoxy, hydroxy, trifluoromethanesulfoneamide or halogen, R₆ represents—SO₂—R₇ or —CO—(CH₂)_(m)-R₈, wherein, R₇, represents lower alkyl,—CH₂COOH, trifluoromethyl, non-substituted phenyl, or phenyl group whichis substituted with lower alkyl, lower alkoxy, hydroxy or halogen, R₈represents carboxyl group, non-substituted phenyl, or phenyl group whichis substituted with lower alkyl, lower alkoxy, carboxyl, hydroxy,halogen, —NHSO₂CF₃ or —NHCOCOOH, m=0 or 1, R₉ represents hydrogen,hydroxy or —OR₁₀ wherein R₁₀ is lower alkyl, —CH₂OCH₃, —CH₂O(CH₂)₂OCH₃or —CH₂SCH₃, A₃ is hydrogen or methyl.
 2. A method for preparing thecompound of formula (III),

wherein, R₂ is —(CH₂)_(n)-A₂-Ph, wherein n denotes an integer of 0-3 andA₂ is single bond or —O—; comprising condensation of a compound offormula (II),

wherein, R₂ is the same as mentioned above; R₁₁ is 4(S)— or4(R)-benzyl-2-oxazolidinone or 1(S)— or 1(R)-2,10-camphorsultam, withisoquinuclidine followed by removal of a chiral auxiliary (R₁₁).
 3. Amethod for preparing the compound of formula (V),

wherein, R₂ is —(CH₂)_(n)-A₂-Ph, whereir n denotes an integer of 0-3 andA₂ is single bond or —O—; comprising reduction of a compound of formula(II)

wherein, R₂ is the same as mentioned above; R₁₁ is 4(S)— or4(R)-benzyl-2-oxazolidinone or 1(S)— or 1(R)-2,10-camphorsultam; with areductant to yield a compound of formula (IV),

wherein, R₂ and R₁₁ are the same as mentioned above; then the hydroxygroup is methylated or halogenated followed by reaction withisoquinuclidine and removal of the chiral auxiliary (R₁₁).
 4. A methodfor preparing the compound of formula (VII),

wherein, R₂ is —(CH₂)_(n)-A₂-Ph, wherein n denotes an integer of 0-3 andA₂ is single bond or —O—; comprising condensation of a compound offormula (VI),

wherein, R₂ is the same as mentioned above; with isoquinuclidinefollowed by hydrolysis of the ester.
 5. A method for preparing thecompound of formula (IX),

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-Ph, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—, R₄ represents lower alkyl,non-substituted phenyl group, or phenyl group which is substituted withlower alkyl, lower alkoxy, hydroxy, methoxycarbonyl, ethoxycarbonyl,trifluoromethanesulfoneamide or halogen, R₅ represents pyridyl,thiazolyl, non-substituted phenyl group, or phenyl group which issubstituted with lower alkyl, lower alkoxy, hydroxy,trifluoromethanesulfoneamide or halogen; R₁₄ is R₄ or R₅, and A₄ is —O—,—S—, or —NH—; comprising condensation of a compound of formula (VIII),

wherein, A₁, R₁, and R₂ are the same as mentioned above; with R₄OH, R₄SHand R₅NH₂.
 6. A method for preparing the compound of formula (XII),

wherein, R₁ represents hydrogen or methyl group, R₂ represents—(CH₂)_(n)-A₂-Ph, wherein n denotes an integer of 0-3 and A₂ is singlebond or —O—, R₆ represents —SO₂—R₇ or —CO—(CH₂)_(m—R) ₈ wherein, R₇represents lower alkyl, —CH₂COOH, trifluoromethyl, non-substitutedphenyl, or phenyl group which is substituted with lower alkyl, loweralkoxy, hydroxy or halogen, R₈ represents carboxyl group,non-substituted phenyl, or phenyl group which is substituted with loweralkyl, lower alkoxy, carboxyl, hydroxy, halogen, —NHSO₂CF₃ or —NHCOCOOH,m=0 or 1; comprising condensation of a compound of following formula(X),

wherein, R₁ and R₂ are the same as mentioned above; R₁₂ isbenzyloxycarbonyl group or tert-butoxycarbonyl group; withisoquinuclidine followed by deprotection of the amino group to give acompound of following formula (XI),

wherein, R₁ and R₂ are the same as mentioned above; and the compound ofgeneral formula (XI) is reacted with R₇SO₂Cl, or R₁₃—CO—(CH₂)_(m)-R₈wherein R₇ and R₈ are the same as mentioned above; R₁₃ is halogen, OH,or OMe, or HP(O) (OPri)₂.
 7. A method for preparing the compound offormula (XIII),

wherein, R₁ represents hydrogen or methyl group, R₂ represents—(CH₂)_(n)-A₂-Ph, wherein n denotes an integer of 0-3 and A₂ is singlebond or —O—, A₃ is hydrogen or methyl; comprising reaction of a compoundof formula (XI)

wherein, R₁ and R₂ are the same as mentioned above; withdiisopropylsquarate optionally followed by N-methylation, and hydrolysiswith acid.
 8. A method for preparing the compound of formula (XVI),

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-Ph, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—, comprising reduction of acompound of formula (XIV),

wherein, A₁, R₁, and R₂ are the same as mentioned above; followed byoxidation to give a compound of following formula (XV),

wherein, A¹, R₁, and R₂ are the same as mentioned above; and thecompound of general formula (XV) is reacted with NaCN or KCN followed byhydrolysis of nitrile group.
 9. A method for preparing the compound offormula (XVII),

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-Ph, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—, R₁₀ is lower alkyl,—CH₂OCH₃, —CH₂O(CH₂)₂OCH₃ or —CH₂SCH₃; comprising reaction of a compoundof formula (XVI)

wherein, A₁, R₁, and R₂ are the same as mentioned above; with R₁₀—X (Xis halogen) followed by hydrolysis of its ester group.
 10. A method forpreparing the compound of formula (XVIII),

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-Ph, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—; comprising reaction of acompound of formula (XV)

wherein, A₁, R₁, and R₂ are the same as mentioned above, withCH₂(COOMe)₂, followed by hydrogenation and hydrolysis.
 11. A method forpreparing the compound of formula (XIX),

wherein, A₁ represents methylene or carbonyl, R₁ represents hydrogen ormethyl group, R₂ represents —(CH₂)_(n)-A₂-2h, wherein n denotes aninteger of 0-3 and A₂ is single bond or —O—; comprising reaction of acompound of formula (XV)

wherein, A₁, R₁, and R₂ are the same as mentioned above, with H₂NOSO₃H.12. A pharmaceutical composition comprising compounds of formula (I) ortheir pharmaceutically acceptable salts, according to claim 1, as activeingredients which have blood glucose lowering activity.